After having accumulated over 15 years of tilapia growing and stocking experience, plus hearing many cases of success and failure from our clientele, I feel compelled to offer some tips for the successful use of tilapia in fishery management down here in Texas.
Here are a set of guidelines to follow for success using tilapia as a management tool:
1. Don't get in a hurry to stock. We normally start getting calls for tilapia in March, but late season cold snaps pose significant risk to the welfare of your tilapia, so we recommend waiting until April/May for most of the state (wait until temps stabilize in the 70s or higher). In addition, tilapia can compete for bass spawning areas if they are stocked too soon.
2. Choose the right supplier for your fish, so that you end up stocking the right type of tilapia. For spring stocking, you will want MIXED SEX ADULT TRUE MOZAMBIQUE tilapia, not nile or blue or hybrid, preferably 1/4lb+ in size for good survival rates and confirmed maturity. Choose a TRUSTED source as your tilapia supplier, and preferably a source that grows their own fish. There are many good reasons for lake and pond owners to take this point seriously. True Mozambique tilapia are the only species that are legal to stock in Texas without a special exotic species permit. True Mozambique tilapia have a poor cold tolerance compared to nile/blue tilapia, which is a desirable trait since tilapia overwintering in your fishery can have negative consequences. True Mozambique tilapia mature at a younger age and smaller size than other species, so they have more reproductive potential and value as a forage fish. Ask your potential supplier for pictures of their product, or visit the fish farm to look for yourself. The main cultured species of tilapia usually can be distinguished by different banding patterns on the caudal fin. Nile tilapia have strong vertical bands, Blue tilapia have interrupted bands, and Mozambique tilapia have weak or no bands on the caudal fin. Mature male Nile tilapia have gray or pink pigmentation in the throat region, while Mozambique tilapia have more of a yellow coloration. Here are some pictures of our True Mozambique tilapia:
3. Prepare your fishery before stocking tilapia. As with most all forage fish species, the degree of reproductive success/recruitment of offspring in any fishery will depend on many factors and conditions. In order to provide for the best conditions for tilapia reproductive success, encourage a plankton bloom first. If your fishery is dominated by submerged aquatic weeds and algae, then take the month of March to work on control of potential nuisance growth and fertilize (if needed) before stocking tilapia. Some of you must be thinking..."but tilapia eat algae, so why treat before stocking?" Once newborn tilapia fry absorb their yolk sac, they need abundant plankton for immediate food, and a plankton bloom also provides cover from predators by reducing visibility. We have determined that tilapia fry can be very vulnerable to predation, and since each female lays 300-1000+ eggs per spawn (vs. 10,000-30,000 for bluegill) favorable conditions are critical for tilapia fry survival, and ultimately the success of your program.
4. Choose the right stocking rate for the situation. If you have a relatively new fishery with few or no predators, then choose a very low stocking rate, such as 5-10lbs per acre. Since tilapia reproductive success is greatly influenced by predator abundance, tilapia can easily overpopulate and dominate a pond with little or no predator pressure. If your fishery has adequate predation pressure, such as an established bass population, then shoot for stocking 10-100lbs of tilapia per acre, depending on your program, budget, etc. If, for example, you are stocking tilapia for algae control in a clear water fishery with a establish bass population, then you can expect minimal tilapia reproductive success due to predation, and you will have to rely on that original batch of tilapia stockers for all of your algae control for the entire season (unless you restock). In this case you may need a high stocking density, such as 50-100lbs per acre. There are a lot of scenarios where tilapia can be a good tool for fishery management. Ask a qualified fisheries professional for stocking rate recommendations for any specific needs.
5. Don't forget about fall tilapia. Many fishery owners/managers don't realize that there are two good opportunities to stock tilapia. The spring/early summer stocking program is straightforward, simply stock mature size tilapia as breeders for the entire season. HOWEVER, if your fishery conditions do not promote successful recruitment of tilapia offspring, you have a second chance to make the program work. Here at Overton Fisheries we typically have an overabundance of tilapia fingerlings in August/September/October, and we offer these at a discounted price (while supplies last) for late-season injection as fall forage. This program works VERY WELL, and this opportunity is overlooked by many. On this program you can get 3-6" size tilapia fingerlings in the late summer/early fall, at a discounted price, with good head count per lb, and they will continue to grow for several months before end of season. If you have had poor tilapia reproductive success in the past, or if your fishery is heavy on predators and light on plankton, then consider taking your tilapia budget and splitting it between two stockings, early season adults and late season fingerlings.
Late Season Fingerlings
6. Grow your own. Utilization of a separate breeder pond for tilapia fingerling production can render significant results. Most importantly, a breeder pond needs to be verifiably free of other fish before stocking, each season. For our special clients who need to stock a breeder pond, we are able to sex our tilapia breeders to provide the correct ratio of males:females for optimum reproductive success. A properly managed breeder pond can render 1000-4000lbs of fingerlings per acre. That's a lot of bait! Now all you need to do is get that forage into your main fishery! Sounds easy enough...but more difficult and involved than you might think. Please place your late season tilapia orders early in the season so that we may accommodate your request.
Just for kicks, here is a pic of one of our "Mixed-Mozies," a result of integration of Hawaiian Gold Mozambique into our stock of Black Mozambique tilapia:
Overton's Mixed-Mozambique Tilapia